Add type and direction infos in Annotation class

background issue https://github.com/Microsoft/azure-maven-plugins/issues/456

There used to be strong dependency between function maven plugin and function java library, and now we change to use java reflect to get attributes from annotation to reduce the dependency (PR https://github.com/Microsoft/azure-maven-plugins/pull/508).
However, we still need to store annotation type and direction infos in our enum class for we can't get them from annotations. So could you please add the infos in annotations of java library, like add an annotation? If so, all needed informations could comming from java library directly.
Besides, could you please update the [function.json scheme](http://json.schemastore.org/function)? Schema could be much helpful in local validation and users could verify and update their code according to schema as well

Comienza con la clase Annotation y los enums de anotaciones existentes; después, revisa la issue de contexto enlazada y el pull request relacionado con reflection para obtener contexto. Actualiza las anotaciones de Java para exponer la información de tipo y dirección necesaria, y actualiza el esquema function.json referenciado para que esos valores puedan validarse.

Escrito por el modelo de indexación a partir del texto del issue.